1. Technical Field
The invention relates to telescopes. More specifically, the invention relates to portable telescopes having an offset in the optical pathway, advanced finder features, and convenient setup and storage features.
2. Description of the Related Art
One of the biggest barriers of entry for a would-be amateur astronomer and one of the most tedious chores to already amateur astronomers is the daunting task of setting up and initially calibrating a telescope. Indeed, the positions of astronomical objects in the celestial sky are based upon a complex spherical coordinate system involving the perpendicular axes of right ascension and declination, determination of which requires a theodolite, a clock, and an accurate knowledge of the observer's latitude and longitude. The theodolite is used to measure the object's angle above the local horizon; the object's declination is then calculated to be the angle between the Celestial Equatorial Plane (CEP) and the North Celestial Pole (NCP). An arbitrary 0° longitudinal line has been defined as a line engraved on a brass plate set in the floor of the Old Royal Observatory in Greenwich, England.
The object's right ascension requires a knowledge of the Local Sidereal Time, being based upon the moment of Local Sidereal Time the object transits the observer's zenith, or local meridian. Also, since the Earth makes one full turn about its polar axis about every twenty-four hours, right ascension is traditionally referred to in hours, from zero to twenty-four. Note, however, that right ascension is converted to degrees, with one hour of right ascension equaling 15°, or 1/24 of a 360° circle. Hours are further divided into finer units of 60 arcminutes, written 60′, or 3600 arcseconds, written 3600″. Furthermore, because the Earth's axis of rotation moves, causing the coordinate grid to shift, an object's right ascension and declination are continually changing. Thus, an object's precise position is date dependent, with the current standard being equinox 2000.0, which means the object's right ascension and declination at the moment the year 2000 began. For example, the star Vega (Alpha Lyra) currently may be found at approximately 18 h 37 m right ascension, and approximately +38 47′ declination.
As can be appreciated, locating astronomical objects and positioning a telescope for observation can be a difficult, frustrating, and time consuming process. Furthermore, once the telescope has been repositioned to observe a second object, a large part of the process must be inefficiently and inconveniently repeated to reacquire the first object. Similarly, once an observer locates a particular object, a second observer must position himself at the vantage point of the original observer. Depending on the relative heights of the observers, this might require bending down, using ladders, etc. Likewise, there are times when a second observer cannot easily reach a first user's height, for example, a wheel-chair-bound observer.
An alternative to setting up a telescope to view astronomical objects is a pure digital solution in the form of a virtual sky map, such as Google™ Sky. However, these pure digital solutions do not satisfy an enthusiast's desire for authenticity and, more importantly, cannot be used to gather actual data in real time.